Nanometer Gold Clusters Protected by Surface-Bound Monolayers of Thiolated Poly(ethylene glycol) Polymer Electrolyte

Wuelfing, W. Peter; Gross, Stephen M.; Miles, Deon T.; Murray, Royce W.

doi:10.1021/ja983183m

Cited by 404 publications

(394 citation statements)

References 9 publications

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“…46,47 However, the Au-S linkage is not strong enough under physiological conditions because of the limited oxidative stability of thiolate species, [48][49][50] as well as the exchange reactions with thiolated compounds that occur inside the body. Thiolatemodified surfaces are also damaged by exposure to light, high temperature and oxygen.…”

Section: Synthesis Of End-reactive Peg For Surface Modificationsmentioning

confidence: 99%

Construction of a densely poly(ethylene glycol)-chain-tethered surface and its performance

Nagasaki

2011

Polym J

113

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Non-biofouling surfaces constitute one of the most important subjects in sensitively and selectively detecting biomolecular events. Poly(ethylene glycol) (PEG) chains tethered on substrate surfaces are well known to reduce non-biofouling characteristics. Protein adsorption onto a PEG-chain-tethered surface is strongly influenced by the density of the PEG chain and is almost completely suppressed by the successive treatment of longer PEG chains (5 kDa) followed by the treatment of PEG (2 kDa; mixed-PEG-chain-tethered surface) because of a significant increase in PEG chain density. To modify versatile substrate surface, PEG possessing pentaethylenehexamine at one end (N6-PEG) was prepared via a reductive amination reaction of aldehyde-ended PEG with pentaethylenehexamine. Using N6-PEG, antibody/PEG co-immobilization was conducted on a substrate possessing active ester groups. After the antibody was immobilized on the surface, PEG tethered chains were constructed surrounding the immobilized antibody. It is interesting to note that the PEG-chain-tethered functions not only as a non-fouling agent but also improves immune response. The hybrid surface was also applied to oligo DNA immobilization. The oligo DNA/PEG hybrid surface improved hybridization, retaining its non-fouling ability. Densely packed PEG tethered chains surrounding antibodies and/or oligo DNA improved their orientation on the surface. Thus, this material is promising as a high-performance biointerface for versatile applications. Keywords: antibody; biosensing; DNA; end-functionalized poly(ethylene glycol); enzyme-linked immunosorbent assay; hybrid biointerface; soft interface INTRODUCTION Specific biorecognition on substrate surfaces has long been utilized in many applications such as biosensing, 1 immunodiagnostics, 2 enzyme immunoassay, 3 western blotting 4 and protein microarrays. 5 Important factors for the improvement in specific biorecognition on surfaces are the suppression of nonspecific biofouling and the suitable orientation of immobilized biomolecules. The former decreases nonspecific noise and the background level, and the latter increases the specific recognition level. To improve the non-biofouling character of surfaces, numerous efforts have been undertaken. In general, natural polymers such as albumin, casein and dextran have been used for blocking on substrate surfaces. 6 These treatments work well and suppress protein biofouling extensively. If extremely high performance is required, however, these blocking treatments are not enough. In addition, natural products, especially those derived from animals, may have undesired contents such as bacteria and viruses, which may affect the user. 7 Under these circumstances, synthetic polymers have been recently suggested as suitable surface blocking agents. Numerous types of water-soluble polymers, such as poly(acrylamide), poly(vinyl alcohol), poly(vinyl pyrrolidone) and poly(ethylene glycol) (PEG), have been investigated so far. Recently, new types of synthetic polymers such as poly(methoxy ...

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Section: Synthesis Of End-reactive Peg For Surface Modificationsmentioning

confidence: 99%

Construction of a densely poly(ethylene glycol)-chain-tethered surface and its performance

Nagasaki

2011

Polym J

113

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“…In contrast to the former two grafting techniques, the " grafting from " approach leads to polymer brushes with high grafting densities, which infl uence the chemical and physical properties of the nanoparticles, especially the wettability properties. Several reports were published where various kinds of polymers such as poly(ethylene glycol) [132,133] , poly(styrene) [134,135] , poly(methacrylamides) [136,137] , poly(methacrylates), [123] poly(vinylpyridines) [129] are tethered by one end to gold nanoparticles by either " grafting to " [122,138] , the in-situ " grafting to " [12] or the " grafting from " [128] technique [82] .…”

Section: Polymer Brushesmentioning

confidence: 99%

Coating matters: the influence of coating materials on the optical properties of gold nanoparticles

Chanana¹,

Liz‐Marzán²

2012

Nanophotonics

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An essential element in the synthesis of nanomaterials based on gold nanoparticles comprises the control over parameters such as size, shape and composition, due to their strong infl uence on the properties of the particles. However, it is the coating material which often plays the primary role in tuning the size, morphology, and even plasmon resonance wavelength or mode multiplicity, as well as colloidal stability and functional versatility, ultimately determining the physical, chemical, optical, electronic and catalytic properties of the nanoparticles. Therefore, it is utterly important to select the adequate wet chemistry synthetic approach with the most suitable coating material for the preparation of gold nanoparticles with the desired requirements. Within this context, this review is focused on describing various types of organic and inorganic coating materials for gold nanoparticles that may notably affect their optical properties by either directly infl uencing the synthesis procedure or by changing their chemical and physical properties upon post-synthetic modifi cations, such that they exhibit novel and useful optical properties.

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“…Similar plasmon shifts have been reported for gold nanoparticles with silica shells in which the higher refractive index of SiO 2 results in higher values of λ max . 13,60 Taton et al prepared core/shell gold nanoparticles by micellar encapsulation of hydrophobically modified gold nanoparticles via a self-assembly approach and reported similar behavior. 48 Comparing to that of the citratecapped gold nanopartilces, the core-shell hybrid gold nanoparticles exhibit larger surface plasmon bandwidth.…”

Section: Resultsmentioning

confidence: 95%

Double Hydrophilic Block Copolymer Monolayer Protected Hybrid Gold Nanoparticles and Their Shell Cross-Linking

et al. 2005

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This paper describes the syntheses of core/shell gold nanoparticles stabilized with a monolayer of double hydrophilic block copolymer and their stimuli responsiveness before and after shell cross-linking. The hybrid nanoparticles consist of gold core, cross-linkable poly(2-(dimethylamino)ethyl methacrylate) (PDMA) inner shell, and poly(ethylene oxide) (PEO) corona. First, diblock copolymer PEO-b-PDMA was prepared via the reversible addition-fragmentation chain transfer (RAFT) technique using a PEO-based macroRAFT agent. The dithioester end group of PEO-b-PDMA diblock copolymer was reduced to a thiol end group. The obtained PEO-b-PDMA-SH was then used to prepare diblock copolymer stabilized gold nanoparticles by the "graftingto" approach. 1,2-Bis(2-iodoethoxy)ethane (BIEE) was utilized to selectively cross-link the PDMA residues in the inner shell. The stimuli responsiveness and colloidal stability of core/shell gold nanoparticles before and after shell cross-linking were characterized by laser light scattering (LLS), UV-vis transmittance, and transmission electron microscopy (TEM). At pH 9, the average hydrodynamic radius 〈R h 〉 of non-crosslinked hybrid gold nanoparticles starts to increase above 35°C due to the lower critical solution temperature (LCST) phase behavior of the PDMA blocks in the inner shell. In contrast, 〈R h 〉 of the shell cross-linked gold nanoparticles were essentially independent of temperature. Core/shell gold nanoparticles before and after shell cross-linking exhibit reversible swelling on varying the solution pH. Compared to non-cross-linked core/shell gold nanoparticles, shell cross-linking of the hybrid gold nanoparticles leads to permanent core/ shell nanostructures with much higher colloidal stability and physically isolates the gold core from the external environment.

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Nanometer Gold Clusters Protected by Surface-Bound Monolayers of Thiolated Poly(ethylene glycol) Polymer Electrolyte

Cited by 404 publications

References 9 publications

Construction of a densely poly(ethylene glycol)-chain-tethered surface and its performance

Construction of a densely poly(ethylene glycol)-chain-tethered surface and its performance

Coating matters: the influence of coating materials on the optical properties of gold nanoparticles

Double Hydrophilic Block Copolymer Monolayer Protected Hybrid Gold Nanoparticles and Their Shell Cross-Linking

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